<i>int</i> v = <s>date</s>.<b>millisecondsSinceEpoch</b>;			<em>// 毫秒(13位) => 1571550449365</em>
<i>int</i> v = <s>date</s>.<b>microsecondsSinceEpoch</b>;		<em>// 微秒(13位) => 1571550449365000</em>